For various medical reasons, such as diagnostic tests or the like, it is often necessary for a physician to obtain a sample of a patient's body. Often, it is required for the physician to take a sample from a soft tissue such as a breast biopsy specimen as opposed to a more rigid structure, such as a bone marrow specimen. Soft tissue specimens generally contain a less rigid structure and are by definition “soft” or easily deformable as opposed to bone marrow structures which are recovered with significant portions of their internal bony trabecular structure intact.
One exemplary surgical instrument for the severing and/or retrieval of biopsy specimens is disclosed in U.S. Pat. Nos. 5,522,398; 5,843,001; and 6,015,391, of which the present applicant is also inventor. Each of these patents is hereby expressly incorporated herein by reference. While these instruments are particularly suited for severing and collecting a more rigid tissue specimen, such as a bone marrow specimen, the instruments are not as effective at severing and/or retaining soft tissue samples. In addition, the concept of recovering a specimen by pushing it toward the handle from the tip of the needle may not be as applicable for soft tissue specimens as it is for bone marrow specimens. An attempt to push the specimen through the needle can result in disruption of the specimen because soft tissue specimens have less structure. Moreover in a long needle, such as an endoscopic SNARECOIL (trademark) needle, the length of the needle would be prohibitive in successfully pushing the specimen out of the proximal end of the needle and recovering an intact sample.
Other conventional procedures and instruments used for obtaining the samples, while not overly complex, almost universally result in excessive patient discomfort and often overly extends the patient's and operator's time and money.